Answer: Applied force.
- A Applied force
- B Acceleration
- C Kinetic energy
- D Impulse
Correct answer: A. Applied force
Explanation: Newton's second law states F = dp/dt: the net external force equals the rate of change of momentum.
Free-body diagram of a block on an incline: weight (mg) resolves into mg sinθ along the slope and mg cosθ into the slope, balanced by the normal force N and friction f.
Concept context
Newton's three laws, friction, circular motion, and free body diagrams.